; EXPECT: sat
(set-logic ALL)
(set-option :incremental false)
(declare-datatypes ((nat 0)(list 0)(tree 0)) (((succ (pred nat)) (zero))((cons (car tree) (cdr list)) (null))((node (children list)) (leaf (data nat)))))
(declare-fun x1 () nat)
(declare-fun x2 () nat)
(declare-fun x3 () list)
(declare-fun x4 () list)
(declare-fun x5 () tree)
(declare-fun x6 () tree)
(check-sat-assuming ( (not (not (and (and ((_ is node) x6) (= x6 x5)) (not (= null (cons x6 x3)))))) ))
